SSL Proxy Profiles are deprecated for several years, meaning they still work but lack current features (e.g. elliptic curve ciphers etc.).
So the recommendation is to move to SSL Server Profile / SSL Client Profile instead, which among others allow you to explicitly select which ciphers to offer.
Besides ciphers, I think also the enabled protocols impact the list (SSLv3/TLSv1.0/TLSv1.1/TLSv1.2).
You can always review a TLS handshake in packet-capture for details, or test against a DP service which FSH is configured with your (Reverse) SSL Proxy Profile definition and then use "nmap --script ssl-enum-ciphers -p <port> <IP/FQDN>".
#DataPower#Support#SupportMigration